The purpose of this study was to investigate the possibility of bamboo extract as natural dye having the effect on atopic dermatitis(AD). To investigate the effect of bamboo extract on AD in vivo, we applied bamboo extract to the AD-like skin lesion the backs of atopic of NC/Nga mice, an animal model of AD. NC/Nga mice were challenged with DNCB(2.4-Dinitrochlorbenzene) to develope AD-like skin lesions. The efficacy of bamboo extract in the NC/Nga mice was evaluated by measurement of the skin lesion severity(NC mouse score), the serum IgE level, epidermal thickness changes, and mast cell number. Bamboo extracts improved skin lesions in NC/Nga mice. The serum IgE levels were decreased after treatment with bamboo extract. Histological examinations revealed a decrease in epidermal thickness and mast cell number after treatment with bamboo extract. To conclude, the topical application of bamboo extract suppressed the progression of AD-like skin lesions.